Severe Thunderstorm Watch 252

Issued

May 5, 2012, 6:46 PM CDT (23:46 UTC)

Expired

May 6, 2012, 1:00 AM CDT

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

2.5 in

Strongest gust expected

60 kt

The North Platte radar (KLNX), 96 km from the middle of the area, began a volume at 23:49 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Two or more tornadoes

5%

One or more EF2 to EF5 tornadoes

2%

Ten or more severe wind reports

20%

One or more gusts of 65 knots or more

20%

Ten or more severe hail reports

70%

One or more hailstones of 2 inches or more

60%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 716May 5, 3:52 PM CDT
• Mesoscale Discussion 721May 5, 6:21 PM CDT
• Mesoscale Discussion 725May 5, 9:51 PM CDT
• Mesoscale Discussion 726May 5, 11:31 PM CDT

737 
WWUS20 KWNS 052349
SEL2
SPC WW 052349
IAZ000-MNZ000-NEZ000-SDZ000-060600-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 252
NWS STORM PREDICTION CENTER NORMAN OK
645 PM CDT SAT MAY 5 2012

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

       EXTREME NORTHWEST IOWA
       EXTREME SOUTHWEST MINNESOTA
       CENTRAL AND NORTH CENTRAL NEBRASKA
       SOUTHEAST SOUTH DAKOTA

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 645 PM
UNTIL 100 AM CDT.

HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 45
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 85 MILES WEST
SOUTHWEST OF MULLEN NEBRASKA TO 35 MILES EAST SOUTHEAST OF
BROOKINGS SOUTH DAKOTA.  FOR A COMPLETE DEPICTION OF THE WATCH
SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

OTHER WATCH INFORMATION...CONTINUE...WW 249...WW 250...WW 251...

DISCUSSION...ELEVATED THUNDERSTORMS WILL LIKELY INCREASE IN
COVERAGE/INTENSITY THROUGH EARLY TONIGHT IN A ZONE OF INCREASING WAA
FROM NRN NEB INTO SE SD.  STRONG INSTABILITY IS PRESENT ABOVE THE
FRONTAL SURFACE...AND STRONG CLOUD-LAYER SHEAR WILL SUPPORT A RISK
FOR ELEVATED SUPERCELLS CAPABLE OF PRODUCING VERY LARGE HAIL.  THE
RISK SHOULD INITIALLY BE CONFINED TO LARGE HAIL...THOUGH THERE WILL
BE SOME RISK FOR ISOLATED DAMAGING WINDS LATER AS STORM COVERAGE AND
COLD POOL PRODUCTION INCREASES.  FARTHER W...SUPERCELLS IN THE
POST-FRONTAL UPSLOPE REGIME IN THE SW NEB PANHANDLE COULD PROGRESS
FAR ENOUGH E TO IMPACT MORE OF SW NEB...BEFORE WEAKENING LATE THIS
EVENING.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 24030.


...THOMPSON

Severe Thunderstorm Watches in South Dakota, 2012Severe Thunderstorm Watches in Nebraska, 2012Severe Thunderstorm Watches in Minnesota, 2012Every severe thunderstorm watch in 2012

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.